Subjects will be randomized to receive either the Phenylbutyrate or placebo tablets for 1 week, with a 2 out of 3 chance of receiving Phenylbutyrate at a standard adult dose, with visits on study days 1, 4, and 7. The study will last an additional 2 weeks to determine whether the effects of the Phenylbutyrate or Placebo persist for any length of time, with visits on study days 14 and 21. Every participant will receive the Genistein during the NPD on days 1 and 7. The dose of Genistein used will not be escalated and will be the same for every participant.